1. Field of the Invention
The present invention relates to a laser processing system having a function for adjusting timing to switch a laser output command with respect to movement of an axis.
2. Description of the Related Art
Generally, in laser processing, it is necessary that a drive axis of a processing nozzle for irradiating a laser beam is moved in synchronization with outputting of the laser. Therefore, in the prior art, a laser oscillator is controlled by a numerical controller (CNC), a laser output command is calculated with the same period as a movement command of the axis, and the laser oscillator is connected to a servo amplifier so that the movement command of the axis and the laser output command are output in the same route, whereby the synchronism between the movement command of the axis and the laser output command is retained.
As a relevant prior art document, JP H10-128564 A discloses an automatic programming device having a start/end code registration part capable of registering a plural kinds of NC codes for cut-start beam ON; and a beam ON/OFF attribute change part for individually changing the kind of beam ON attribute added to a required part of a cut shape plotted on a screen by an input from a man-machine interface part, within a range of registrable kinds of the NC code for cut-start beam ON.
JP H09-108863 A discloses a laser processing device having a delay time calculating means for calculating a delay time before a movement path of a processing head approaches a target coordinate in a movement command based on data with respect to the movement command and a time constant of the acceleration when a beam on-off command is outputted; and a laser output control means for controlling the output of the laser beam of a laser oscillator and executing the beam on-off command after counting the time by the delay time calculated by the delay time calculating means when the laser output control means receives the beam on-off command.
Further, WO 2000/053363 A1 discloses a laser processing device having a program analyzing means for analyzing a processing program and outputting a movement command for each axis and an on/off command to turn on/off a laser beam; an interpolating means for performing interpolation according to the movement command and outputting a movement distance to a servo amplifier; a movement distance setting means for setting a movement distance for delay motion; and a beam on/off delay means for delaying the beam on/off command which is output to a laser oscillator, based on the actual movement distance after the on/off command is output and the movement distance for delay motion.
In the conventional laser processing device as described above, the movement command for the axis and the laser output command are synchronized with each other. However, a delay in a response of an excitation power supply of a laser oscillator, a delay time from when a laser beam is irradiated onto a workpiece to when the workpiece is actually cut, and a delay in of a data transfer time from a CNC to the oscillator, etc., are not considered in the conventional processing device, whereby laser processing accuracy may be deteriorated.
In the technique of JP H10-128564 A, although a condition of piercing can be set by the automatic programming device, the delay in the response of the laser excitation power supply is not considered. Further, the delay in the response of the laser excitation power supply is also not considered in JP H09-108863 A or WO 2000/053363 A1.